Heat transfer device with capillary condensate drain



Jan. 6, 1948. A. o. BROTHERS HEAT TRANSFER DEVICE WITH CAPILLARY CONDENSATE DRAIN Filed July 1, 1944 Patented Jan. e, 1948 HEAT TRANSFER DEVICE WITH CAPILLARY CONDENSATE DRAIN Alvin 0. Brothers, Evansville, Ind., assignor to Serve], Inc., New York, N. Y., a corporation of Delaware Application July 1, 1944, Serial No. 543,088

13 Claims.

1 My invention relates to heat transfer fins and more particularly to self-draining heat transfer fins for use on a high temperature evaporator in the food storage compartment of a domestic re frigerator.

In domestic refrigerators, particularly in the food storage compartment equipped with a high temperature evaporator, the air circulating through the compartment and over and through the evaporator and heat transfer fins deposits moisturethereon which is condensed. This condensed moisture accumulates and in time trickles down over the surface of the fins and drips off the lower edges thereof. Heretofore, drip pans have been provided under the entire evaporator in order to catch this condensed moisture and prevent it from falling on to the food in the storage compartment. However, this arrangement has not proven entirely satisfactory because it interferes with the free circulation of air through the heat exchange fins and thereby lowers the efficiency of the refrigerator.

is a drain trough which is located directly under the rear lower edges of the fins l2 and is used It is an object of my invention to provide selfdraining heat transfer fins which drain condensed moisture away from the fins Without interfering with the free circulation of air through the food storage compartment and over the heat exchange fins.

These and other objects of my invention will become more apparent when considered in connection with the following description and accompanying drawing which forms a part of this specification and wherein:

Fig. 1 is a partial perspective view of a refrigerator cabinet, showing my improved heat transfer fins attached to the high temperature evaporator located therein;

Fig. 2 is a side view, partly in section, of one form of my improved heat transfer fins;

Fig. 3 is a side'view similar to Fig. 2 illustrating a second embodiment of my invention;

Fig. 4 is a side view similar to Fig. 2fillustrating a third embodiment of my invention;

Fig. 5 is a sectional view taken on line 5--5 of Fig. 2; 4

Fig. '6 is a sectional view taken on line 6--6 of Fig. 3;

Fig. 7 is a sectional view taken on line 1-1 of Fig. 4; and

Fig. 8 is a partial sectional view of a fourth embodiment of my improved fin.

- Referring now to Fig. 1, l designates generally the food storage compartment of a domestic re frigerator provided with a high temperature evaporator Il equipped with'self-draining fins l2. I3

to convey condensed moisture from said fins into a receptacle I4. I

Referring now to Figs. 2 and wherein one embodiment of my invention is illustrated, the heat transfer fin I2 is formed of fiat sheet metal with sleeves l5 extending from the mid-longitudinal portion thereof. These sleeves l5 are adapted to fit around the evaporator conduit I6 in intimate heat transfer relation and may be welded or otherwise secured thereto. A U-shaped trough I1 is attached to the lower portion of the fin I2 in any conventional manner as by welding, soldering or the like, and provides capillary passages l8 and IS on opposite sides of said fin. This trough I1 is provided with a plurality of spaced capillary openings along the lower edge thereof. After these fins have been assembled on conduits l6 a strip of wire screen 2| of relatively close mesh is attached as by Welding, soldering or the like, along the lower portion of the rear vertical edges of the fin's, as shown in Fig. 2. This strip of wire screen extends from one fin to the next across the length of the evaporator.

In theoperation of the embodiment of my in- I vention illustrated in Figs. 2 and 5, condensed moisture that accumulates on the fins l2 trickles down over each of the faces thereof and is picked up by the capillary passages l8 and I!) which convey said moisture to the lower right corner of the fin, as viewed in Fig. 2 and from there the condensed moisture is picked up by the wire screen 2| which conveys it to the trough l3. Any conr densed moisture that accumulates on the outside of the U-shaped trough l1 flows to the lower portion of said trough and passes through capillary openings 20 into the trough.

Referring nowto Figs. 3 and 6 wherein a second embodiment of my invention is illustrated, numeral 22 designates a heat transfer fin generally similar to the fin l2 illustrated in Fig. 2, except that here the bottom portion of the fin is bent in such manner as to provide capillary channels 23 and 24, which collect the moisture condensed on the opposite faces of said fin. In the operation of this embodiment of my invention, the condensed moisture as it accumulates on the faces of Referring now to Figs. 4 and 7, wherein a third embodiment ,of my invention is illustrated, nu-

meral 25 designates a heat transfer fin generally similar to the fin l2 illustrated in Fig. 2, except that here the fin 28 is provided with a U-shaped member 28 formed of relatively close mesh wire screen which extends longitudinally along the lower margins of said fin and under the bottom edge thereof. This fin operates in substantially the same manner as fins l2 and 22 described above in that moisture that is condensed thereon is picked up by the wire screen and by capillary action is conveyed to the drain trough 13.

Referring now to Fig. 8, wherein a fourth embodiment of my invention is illustrated, the heat transfer fin 21 is generally similar to the fin l2 illustrated in Figs. 2 and 5, except that here instead of a U-shaped trough the lower portion of the fin is provided with a fiat strip of metal 28 on each side thereof and spaced. therefrom to form capillary passages 29. 30 along the lower margins of the fin. Strips 28 may be attached to the fi-n in any conventional manner as by welding, soldering or the like. Here again, condensed moisture that accumulates upon the fin 2'! is picked up by the capillary passages 29 and 30 and is conveyed to a common trough.

As shown in Figs. 1;. 2, 3 and 4, my improved heat transfer fins are arranged on the evaporator so that the lower longitudinal edges thereof are slightly inclined downward from the front to the rear of the evaporator.

While I have illustrated and described four specific embodiments of my invention and have mentioned only one particular use for it, it is obvious that it may take other forms and that it has other uses. My improved self-draining heat transfer fins may, for example, be used with any heat exchange device wherein moisture. is apt" to accumulate on the heat transfer fins and wherein some means must be provided for disposing of said moisture. Therefore, my invention is to be limited only by the following claims.

I claim:

1. A self-draining heat transfer fin comprising a relatively fiat member provided with capillary passages along the lower margins thereof for conveying condensed moisture therefrom.

2. In an evaporator, a conduit provided with a plurality of heat transfer fins, each of said fins comprising a relatively fiat sheet metal member forming at least two heat transfer surfaces and provided with means forming capillary passages along a portion of each of said surfaces for draining accumulated moisture therefrom.

3. In a heat transfer device, a conduit for flow of heat transfer medium therethrough, a plurality of vertically disposed heat transfer fins connected to said conduit, and each of said heat transfer fins being provided with means forming capillary passages along lower margins thereof.

4. In a, food storage compartment, a refrigerant evaporator provided with heat transfer fins arranged for free circulation of air thereover, each of said fins including vertically extending portions upon which moisture from said air may condense and accumulate, and means on the lower edges of said vertically extending portions forming capillarypassages for conveying condensed moisture from said fins.

4 cated below said heat transfer fins at one end of said capillary passages.

6. A heat transfer fin comprising a sheet of metal, and a plurality of strips of metal connected to said sheet of metal along one edge thereof and cooperating therewith to provide a plurality of capillary passages.

7. A heat transfer fin comprising a sheet of metal, and an element U-shaped in cross-section extending along one edge thereof and cooperating therewith to provide a plurality of capillary Y passages.

5. In a refrigerator, an evaporator provided with a plurality of heat transfer fins, each of 8. In a heat exchange device, a conduit for flow of heat exchange medium therethrough, a plurality of heat exchange fins connected to said conduit, each of said heat exchange fins comprising a-vertically disposed sheet of heat conducting ma-- terial, and an element U-shaped in cross-section extending over one edge of said sheet and cooperating therewith to provide a plurality of capillary passages.

9. A heat transfer fin comprising a sheet of metal, an element U-shaped in cross-section extending along one edge thereof and cooperating therewith to provide-a plurality of capillary passages, and said U-shaped element being provided with a plurality of capillary openings in the lower portion thereof.

10, In a heat exchange device, a conduit for fiow'of heat exchange medium therethrough, a plurality of rectangular vertically disposed heat exchange fins connected to said conduit, each of said fins being provided with structure along a lower edge thereof forming capillary passages, and connecting means between said fins along another edge thereof forming additional capillary passages.

11. A heat transfer fin comprising a sheet. of metal having one margin thereof bent in the form of a plurality of reverse curves to provide a plurality of capillary channels.

12. In a heat exchange device, a conduit for flow of heat exchange medium therethrough, a plurality of heat exchange fins connected to said conduit, each of said fins comprising a vertically disposed sheet of heat conducting material, a portion of the margin thereof being bent in the form of a plurality of reverse curves to provide a plurality. of capillary channels.

13. A heat transfer fin comprising a vertically disposed sheet of metal, and astrip of wire screen attached to the lower edge of said sheet of metal and cooperating therewith to provide a plurality of capillary passages for conveying condensed moisture from the lower edge of the fin.

ALVIN O. BROTHERS.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Wichmann Aug. 5, 1941 

